Method of charging refrigerating systems



F 17, 1942. s. s. mcLoY METHODOF CHARGING REFRIQERATING SYSTEMS Fi led m16. 1940 Q m P w m E REFR/GiQANr BOMB COMDRE 55 Ol? A m .R

CONDENSER INVENTOR GQAHAM S. Ma 61.0w

ATTOR? WITNESSES: I 4A. M 4; M 946 Patented Feb. 17, 1942 Graham S.McCloy, Springfield, Mass, assignor to Westinghouse Electric 8;Manufacturing Company, East Pittsburgh, Pa., a corporation ofPennsylvania Application May '16, 1946, Serial No. 335,441

8 Claims.

My invention relates to refrigeration apparatus, and more particularlyt?) a method and apparatus for charging a refrigerating system withrefrigerant and lubricant and for removing noncondensable gases from thesystem.

In charging a-closed refrigerating system it is necessary for severalreasons to remove substantially all noh-condensable gases such as airfrom the system. The presence of non-condensable invention as will beapparent from the following description and claims taken-in connectionwith the accompanying drawing forming a part of this application, inwhich the single figure of the drawing is a, diagrammatic view of arefrigcrating system to which my invention is applied,

gases in the system is objectionable for several 10 reasons as is wellknown in the art. For example, the presence thereof causes high headpressures in the high'pressure side of the system, and hence reduces theefliciency of the system.

Heretofore, refrigerating systems generally id have been charged withliquid refrigerant by first drying the refrigerating system with warmair or inert gas and then evacuating the system with high vacuumapparatus. The apparatus for performing the evacuation portion of theprocess is expensive and slow in operation and, in addition, therefrigerant and lubricant with which the system is afterwards chargedcontains non.- condensable gases which are not removed by priorevacuation. Furthermore, such a system.

is not conducive to mass production methods wherein the refrigeratingsystems during assembly and charging are preferablyydisposed on .movingconveyors. This invention is an improvement on the systems disclosed andclaimed Referring specifically to the drawing for 'a detaileddescription of the .invention, the refrigerating system includes ahermetically-sealed motor compressor unit l0 including a compressor H, amotor l2 for driving the compressor and a casing Iii-enclosing the motorand compressor, In normal operation a lubricant reservoir is disposed inthe hermetically sealed casing ii for lubricating the moving parts ofthe com.- pressor unit-J0 such as the bearings 15 and I8. The inlet ofthe compressor shown at H is connected directly to a compressor head Hiso that refrigerant vapor is, withdrawn from an evaporator l9 through aconduit 2| and enters the compressor H without entering the interior ofthe sealed casing l3. The compressor ll discharges high pressurerefrigerant gas into the casing I3 so that the interior of the casingI3- contains gas at substantially condenser pressure. The high pressuregas from the casing I3 is conveyed to a. condenser 22 through a conduit23, Refrigerant is condensed. in the condenser 22 by the cooling actionof air which is forced over the condenser by amotordriven fan 24.

. a suitable screen 25 to a capillary tube 26 which It is an object ofthe present invention to 5 regulates the flow of condensed refrigerantto turned to the compressor it through. the con- Ii; is another objectof the invention to charge 40 a refrigerating system with bothrefrigerant and .lubricant bythe container methods disclosed in theaforesaid patents wherein both the refrigerant and lubricant forinitially charging the system are contained in a container attached tothe system during ch'arging.

It is a further object of the invention to charge a refrigerating systemwith both refrigerant and lubricant by the container methods disclosedduit 2| and the cycle is then repeated. The sys-' -tem is so designedthat, at least under certain conditions, a mixture of liquid and gas isforced through th'e capillary tube 26, whichfact is important in thefurther operation and description of the invention.

' In accordance with the present invention, a

, .in the aforesaid patents and in which the mov- 50.

charging drum or vessel This provided, which vessel 21 containssubstantially the exact charge of refrigerant and lubricant for chargingthe refrigerating system, both the refrigerant and lubricant chargehaving been carefully measured by weight. The refrigerant may be, forexample, dichlorodifluoromethane, sold under the trade name of Freon-12and the lubricant is preferably a high -grade mineral lubricant. Thedrum 21 is connected to the interior of the sealed casing I3 by aconduit 28 having a hand valve These and other objects are effected by.my

29 therein, which conduit, 28 is attached to a welded to an openingcrating system is completed and before it is condensable gases presentin charged, the system is first dehydrated, which is preferably effectedby subjecting the same to a flow of warm dry airor inert gas for asumcient time to substantially remove all the moisture from the system.After dehydration, the system, still filled with warm air or inert gas,

mospheric pressure and the entire systemis above room temperature,having been heated by the warm dry air or inert gas used for drying sothat very little, if any, air from outside the system will enter it. v

The compressor may now be operated'for a short period, for example,about 5 minutes to\ effect partial evacuation of the low pressure sideof the system. This operation is also known as' auto-evacuation, sinceit is effected by operation of the refrigerant compressor. Thecompressor withdraws non-condensable gases present in the. low pressureside ofthe system and discharges such gases to atmosphere through, theopening The pressure in the low pressure side of the system is therebyreduced to about 25 inches of vacuum or lower. The auto-evacuation stepis, however, optional as the container 21 may be made of sufficient sizeto containall the nonthe system without auto-evacuation. I J

The drum 2'! and conduit-28 are then connected to the conduit 30 in .thesealed casing I3 I, with the hand valve 29.closed and preferably withthe compressor H inactive. Afterthe drum 21 and conduit 28' have'beenconnected,

the hand valve 29 is opened and substantially all of the refrigerant andlubricant contained in the vessel 21 flows through conduit 30 andopening -3| into the sealed casing 13, by gravity, It'will, therefore,be apparent that lubricant ispresent in the'lsealedca sing very soonafter the pinched off below the valve 29 and sealed.

valve 29 is opened .to provide for lubrication of r the bearings I5 andii. In addition to the gravity flow of refrigerant into the sealedcasing l3 the refrigerant pressure ,in the vessel 2'! at room ontemperature is usually sufficient, to assist the gravity flow ofrefrigerant and lubricant. This is true of refrigerants, such as F 12,which have a pressure above atmospheric, at room temperacant M in thesealed casing l3. The non-con densable gases which are contained in thesystem at this time are circulated throughout the system 'withtherefrigerant since, as stated heretofore, the system is designed so thatthe cacs pillary tube 26 will pass a mixture of gas and liquid underthese conditions. The compressor, therefore, removes gaseous refrigerantvapor'and non-condensable gases from the low pressure side of the systemand discharges them into the high pressure side of the system includingthe interior of the sealed casing l3, the vessel 21 and the condenser22. Most 'ofthe'refrigerant is con- I densed in the condenser so that amixture of liquid refrigerant and gaseous fluid, both re- 76 frigerantvapor and non-condensable'gases, flows through the capillary tube 26.

A mixture of gaseous refrigerant at high pressure and non-condensablegases also flows through the conduits 30 and 28 and into the ves- Sci21. Because of the flow of gases into the was-- sel 27 the pressuretherein increases. bomb is intimately connected with the high side, thepressure'ln it and the high side will rise at substantiallythe samerate. As the condensing pressure is approached, refrigerant vaporcontained in the mixture begins to condense inasmuch as the vessel 21 isexposed to the ambient atmosphere which is usually at the sametemperature as the air circulated over the condenser 22 by the fan 24.The liquid refrigerant resulting from-such condensation drains bygravity back into the system and tends to reduce the pressure thereinsufficiently to effect the abovementioned flow of fluid mixture from thesealed casing l3 to the vessel 21. The non-condensable gases enteringthe vessel 21 are not condensed so that they accumulate within thevessel 21. During this time, non-condensable gases contained in therefrigerant and lubricant are also removed and are collected in thevessel 21. After the refrigerating system has been operated for asufiiclent time, for example, an hour, to collect substantially all thenon-condensable gases in the vessel 21, the tube 30 is preferably Fromthe foregoing, it will be apparent that -I have provided an improvedmethod of charging both refrigerant and lubricant into a refrigform, itwill be obvious to. those skilled in the art that it is not so limited,but is susceptible of various changes and modifications withoutdeparting from the spirit thereof, and I desire, therefore, that onlysuch limitations shall be placed thereupon as are specifically set forthin the appended claims.

What I claim is:

l. Th method of charging a refrigerating system including an evaporator,a compressor, 'a condenser and an expansion device, with refrigerant andlubricant and removing non-condensable gases from said system, whichmethod comprises connecting to the system a container containingrefrigeranfand lubricant for charging the system, transferringrefrigerant and lubricant from the container to the system, transferring-non-condensable gases from the system to the container by operating thecompressor to effect flow of a mixture of non-condensable gases andrefrigerant vapor into the container, condensing refrigerant vapor inthe container and returne ing the refrigerant condensed in the containerto the system.

2. The method set forth in claim 1 and further including closingcommunication between the system and the container and disconnecting thecontainer from-the system.

Since the "the container from the casing,

3. The method of charging and removing'noncondensable gases from arefrigerating system including an evaporator, a condenser, an expansiondevice, and a c'ompresson enclosed in a gastight casing, which methodcomprises connecting; to said casing a container containing refrigerantand lubricant for charging the system, transferring refrigerant andlubricant fromthe container to the system, transferring non-condensablegases from the system to the container by operating the compressor toeffect fio.w of a mix- 7. The method of charging and removingnoncondensabie gases from a refrigerating system I including anevaporator, a condenser, an expanture of non-condensable gases andrefrigerant vapor into the container, condensing refrigerant vapor inthe container and returning the refrigerant condensed in the containerto the system.

4.- The method of charging and removing noncondensable gases from arefrigerating system including an evaporator, a condenser; an expansiondevice and a compressor disposed in an enclosed casing in which highpressure refrigerant discharged from the compressor'is present,

which method comprises connecting to said'cas-- ing a containercontaining refrigerant and lubricant for charging the system,transferring refrigerant and lubricant from the container to the'system,transferring non-condensable gases from the system to the container byoperating the compressor to efiect flow of a mixture'ofrnoncondensablegases and refrigerant vapor into the container, condensing refrigerantvapor in the containerand returning the refrigerant con-' 'densed in thecontainer to the system.

5. The method'setforth in .claini 4 and further including'closingcommunication between the container andthe casing and disconnecting 6.Themethod of charging and removing noncondensable gases from arefrigerating system including an evaporator, a condenser, anexpansiondevice, and a motor and compressor disposed in an enclosed casing, whichmethod comprises connecting to said casing a container containingrefrigerant and lubricant for charging the syssion device, and a motorand compressor disposed in an enclosed casing in which high pressurerefrigerant is present and which casing connects with said condenser,which method comprises l, connecting to said casing a containercontaining refrigerant and lubricant for charging the sys-- tem,transferring refrigerant and lubricant from the container to the system,transferring noncondensable gases from the system to the container byoperating the compressor to effect flow of a mixture vof non-condensablegases and refrigerant vapor into the containen condensing refrigerantvapor in the container and returning the refrigerant" condensedLinthecontainer to the system.

, tern, transferring refrigerant and lubricant from the system. c

8. The method of charging and removing noncondensable gases from arefrigerating system' and including an evaporator, a condenser,an'expansion device, and a compressor. which method comprises connectingto the system a container containing substantially the exact initialcharge of both refrigerant and lubricant for the system,

transferring refrigerant and lubricant from thecontainer to the system,transferring non-condensable gases from the system to the container byoperating the compressor to effect flow of a mixture of non-condensablegases and refrigerant vapor into the co'ntainer condensing refrigerantvapor in'the container and returning the refrigerant condensed in thecontainer to GRAHAM s. MccnoY.

